As a test device for testing electric characteristics or adequacy of a semiconductor wafer or the like object to be tested, a test probe has been used including a plurality of probes for electrical connection between a tested contact point (terminal, bump) of the object to be tested and a testing contact point (pad) of a test circuit, and a probe card for supporting these probes.
With development of technology, the semiconductor wafer has become larger and a semiconductor has become smaller, thereby increasing the number of pads formable on one sheet of semiconductor wafer. In result, a distance between semiconductor pads has to become narrower. Likewise, there is a need of more densely arranging a plurality of probes on the probe card as a pitch between the pads becomes narrower.
In general, the probe card employs so many microelectromechanical system (MEMS) probes. During the test, the MEMS probe presses the contact point to be tested of the object to be tested against one portion toward a test circuit, and thus a middle elastic deformation portion is deformed. In this case, the other contact portion of the MEMS probe slides and moves in an opposite direction to the buckling direction of the elastic deformation portion on the pad of the test circuit (interposer), and therefore a problem arises in that the contact is not sure. Further, the conventional MEMS type probe card is diagnosed as the whole failures or defects of the probe card even when just one among the plurality of MEMS probes is defective or damaged as repetitively used in the test. Besides, the contact portion of the MEMS probe to be in contact with the tested contact points (terminal, bump and pad) of the object to be tested may be increased in contact resistance as a tip is worn or contaminated by the repetitive tests, thereby lowering reliability.
The plurality of MEMS probes are mounted to upper and lower support members arranged in parallel leaving a space therebetween. In this case, one contact portion of the MEMS probe slides on the support member in a lengthwise direction and therefore does not have a great effect on the support member. However, the other contact portion of the MEMS probe has a bad effect on the support member because of the elastic deformation portion deformed by lengthwise compression, and therefore lowers the contact accuracy and reliability of the MEMS probe.